Microorganisms coexist in nature as communities and engage in a variety of interactions, resulting in both collaboration and competition between individual community members. Advances in microbial ecology have revealed high levels of species diversity and complexity in most communities. Microorganisms are ubiquitous in the environment, inhabiting a wide array of ecosystems within the biosphere. Individual microorganisms and their respective communities play unique roles in environments such as marine sites (both deep sea and marine surfaces), soil, and animal tissues, including human tissue.